The youth is urged once
again not to throw away without regard the beauty which is his to
perfection.
It is Nature's gift, but only given on condition that it is used to
profit
the world, that is, by handing it on to future generations. An analogy
is
drawn from money-lending: the usurer should use his money wisely. Yet
the
young man has dealings with himself alone, and cannot give a
satisfactory
account of time well spent. If he continues to behave in such a way,
his
beauty will die with him, whereas he could leave inheritors to benefit
from
his legacy.

1.
Unthrifty = Unsaving, wasteful., prodigal.
loveliness - this is
personified as the youth.
The youth is beauty itself.
1-2. Why dost thou spend/ upon thyself - As well
as the financial
sense of squandering wealth and resources, this also has a secondary
sexual
reference of emitting semen . Compare : He wears his honour in a box unseen
That hugs his kicky wicky here at home,
Spending his manly marrow in her arms,
Which should sustain the bound and high curvet AW.II.3.272-5.

2. Upon thy self thy beauty's
legacy?

upon thy
self
- see the note above. The implication is that all his pleasure is
wasted
upon himself. thy beauty's legacy = the riches that your
beauty should leave to
the world when you are gone (your children). The legacy of beauteous
children
should be created by his semen which he is wasting instead in frivolous
self pleasure.

3. Nature's
bequest gives nothing, but doth lend,

3.
Nature's bequest =
thequalities, talents, attributes, which are
provided by Nature at birth. Nature, however, does not give outright,
but
only makes a loan. She expects repayment of the loan with interest (in
the
form of gifts to the world).

4. And being frank she
lends to those are free:

4.
frank = generous, liberal; to those are free = to those who are open
hearted, free spirited.
Nature expects a reciprocal response to her gift.

5.
Then, beauteous niggard, why dost thou abuse

5. niggard
= miserly person; stingy
and selfish individual. abuse = ill treat. Also with a suggestion of
self-abuse, masturbation.
The use of niggard(ing) here and in I.12 in a
similar context suggests
a slang meaning of tosser, wanker.

6.
The bounteous largess given thee to give?

6. The
inheritance (of beauty etc.) which was
given to you so that you might pass it on. largess
= generous bestowal
of good qualities.

7.
Profitless usurer, why dost thou use

7. The
comparison of the youth with a usurer
(money-lender), albeit a profitless (unsuccessful) one, is not very
flattering.
Perhaps it was meant to stir him into action which would remedy the
situation.
use is intended both in the technical sense of
lending money as a
usurer, as well as that of making use of (his beauty) by procreating.

8.
So great a sum of sums, yet canst not live?

8. So
great a sum of sums - Usurers had
large sums of money at their disposal. They performed financial
services
which are nowadays done by banks. yet canst not live - the poet here compares
the usurer who makes
a comfotrtable living from the interest he charges, with the youth who
has
so much wealth of beauty, yet cannot live (survive) into the future.

9. For having traffic with
thy self alone,

9. i.e by
not dealing in the commodities which
nature has bestowed upon you (nobility, beauty, wealth). The sexual
meaning
of masturbation is fairly explicit.

10.
Thou of thy self thy sweet self dost deceive:

10. You
deprive yourself of children, who are,
in a sense, yourself; you deceive, cheat yourself. of
thy self
could mean 'by your own action'. deceive = cheat.

11.
Then how when nature calls thee to be gone,

11. Then
how - the question is taken
over by What acceptable audit in the next line. The
compound question
may be read as 'How will you give an account of yourself and your
behaviour
to Nature when she calls (when you die) and what audited record of
yourself
will you provide.

12. What acceptable audit
canst thou leave?

11, 12.
Taken together the two lines seem to
mean 'How is it that, when your time of death comes, you will not be
able
to render a satisfactory account of yourself?' (See note to line
above).
Strictly speaking the term audit is applied to a
check which is made
on accounts after they have been presented, but also, by extension, it
appears
to mean the accounts themselves. It is based on the Latin Audite,
(and spelt thus in 49 and 126), and is the imperative of the verb audire,
to hear. Hence 'Hear! Listen! Be heard!' is the implied translation,
and
it indicates the hearing of accounts presented before a court, or
tribunal,
or in some such official setting.

13. Thy unused beauty must be
tombed with thee,

13. Here
there is also a secondary (primary?)
sexual meaning. Your beauty (seed) should be used for procreation. If
used
in such a way, it would create progeny, a child who would be the
inheritor
of that beauty. But if unused, by being spilt and wasted then etc. must be tombed = cannot avoid being entombed.
(Your seed would be
buried uselessly in your lap). Your children would be unborn, forever
entombed.

14. Which, used, lives
th' executor to be.

14. Which
refers to 'thy beauty'. If
it is used, it creates children, who would interpret and present you as
you were to the world. lives
th'executor to be
= lives in the future as your children, as the inheritor
and administrator of your beauty.